In the prior art, patents such as U.S. Pat. No. 2,188,846, U.S. Pat. No. 2,201,827, U.S. Pat. No. 7,237,460, CA2356549, U.S. Pat. No. 6,282,992B1, and US2004139823, U.S. Pat. No. 7,237,460B2 and EP1215014A2 have put forward various conventional art of a ratchet wrench. The conventional art in the early period has advantages, but still needs continuous improvement.